Textile machine



Nov. 28, 1950 A. G. B. METCALF 2,531,944

TEXTILE MACHINE Filed Feb. 4, 1946 3 Sheets-Sheet 2 ELECTRONIC RELAY mow6 r Nov., 28, 1950 A. G. B. METCALF 2,531,944

TEXTILE MACHINE Filed Feb. 4, 1946 3 Sheets-Sheet 3 26 0: 11 ALARMELECTRONIC g I RELAY I 1 4; P H

ELECTRONIC RELAY II Z ELECTRONIC RELAY Patented Nov. 28, 1950 UNITEDSTATES PATENT OFFICE TEXTILE MACHINE Arthur G. B. Metcalt, Milton, Mass.Application February 4, 1946, Serial No. 845,410

11 Claims.

The present invention relates in general to textile and similarthread-handling machines, and in particular to the combination with suchmachines of electrical apparatus for detecting the breakage of a thread.

Heretofore, it has been known to provide travelling threads, filaments,and the like, as for example the threads of warping frames or creels intextile machines, with so-called drop wires or equivalent contactordevices which stop the machine or give an alarm signal by completing anelectrical circuit upon the breakage of a thread. Such arrangements arecomplicated, dangerous, and uncertain in operation due to the fact thatthe currents involved are usually large, so that the closing of acircuit by a drop wire contactor causes considerable sparking, which,with the lint and dust normally present in the atmosphere around themachine, creates an ever-present hazard of fire and dust explosion.Furthermore the contacts frequently become fouled resulting in failureof the device and the machine may continue to function even though athread may have been broken.

In the present invention, it is proposed to provide an electronicrelay-amplifier between the contactor device and the alarm or motor stopmechanism, so that an extremely minute current is sufiicient to efiectoperation, thus greatly reducing the hazard of fire or explosion, andproviding reliable filament-break detection and stop motion even uponpoor contact of the drop wire contactor.

It is accordingly an object of this invention to provide in a machinefor weaving, spinning, or the like, a filament-break detection apparatuswhich operates positively and reliably under any conditions in which itmay normally be used.

It is another object of this invention to provide such filament-breakdetection apparatus which requires only a very minute current to effectoperation, thereby minimizing the dangers oi fire and explosion.

It is a further object of this invention to provide such apparatus forsimultaneously indicating the breakage of a filament, and shutting downthe machine.

It is a still further object of this invention to provide thread-breakdetection apparatus of the type described for a loom or the like havingmore than one bank of travelling threads which will permit readyidentification of the bank in which a broken thread exists.

It is still another object of this invention to provide such threadbreak detecting apparatus in loom a multi-bank loom or the like whichwill permit ready identification of the bank in which a broken threadexists and simultaneously interrupt the operation of the loom.

Other objects and features of the present invention will become apparentfrom the following description. The description refers to the drawingsin which:

Fig. 1 illustrates partly in electrical scheme and partly in perspectivethe essential elements of the invention;

Fig. 2 illustrates the invention as applied to a having three banks orwarp-forming threads? Fig. 3 illustrates the invention as adapted toprovide an indication of the bank in which a broken thread exists in theloom of Fig. 2;

Fig. 4 illustrates the invention as further adapted to providesimultaneously an indication of the bank in which the broken threadexists and interruption of the motor power to the loom;

Figs. 5 and 6 illustrate other types of circuit completing devices thatmay be used in place or the drop contactors illustrated in Fig. 1.

While it will readily be apparent that this invention will provideimproved filament-break detection for any filament-handling machine, thedescription is directed only to the application of the invention to atextile machine as a convenient illustration. Accordingly, in Fig. 1,thread-break detection apparatus 15 as commonly found in a loom is shownenclosed in a dotted line box and comprises first and second bars ofconductive material, l0 and H respectively, substantially parallel andseparated from each other by suitable insulating material H. The barsrun across the loom beneath threads I4, and conductive drop contactorsI3, made of as copper, are supported each upon an individual thread. Thecontactors l3 are each in constant slideable contact with the first barl0 and are supported above the second bar ll so that when a supportingthread l4 breaks, the associated contactor l3 will fall and establishelectrical contact between the bars I 0 and H.

As hereinabove stated, it has hitherto been customary to employ the dropcontactors I3 as switches in a circuit having relatively high currentand thereby to close the circuit to operate a relay or other operatordevice. In accordance with the present invention, an electronic relayIi, shown enclosed in a dotted line box, which may be 01' any suitabletype, as for example that disclosed in Patent No. 2,357,371, to WilliamF. Wolfner, II, dated September 5, 1944, is interposed bea suitablematerial, such tween the detecting apparatus and the operator means,which may comprise a magnetic relay 29 controlling a contact 35, so thata relatively small current controlled by the contactors 13 will effectoperation of the operator means, through the electronic relay. Theelectronic re lay apparatus 16 comprises generalh' an electronicdischarge device or tube 20 having at least an anode 2i, a cathode 22and a control grid 23. The electron tube 20 is supplied with alternatingpotent'al at terminals and 26. Bar In may be connected to terminal 26 orboth bar and terminal may be grounded as shown. The energizing coil ofthe relay 29 is connected in the anode, cathode circuit of tube 29. Thesecond bar I l is connected to the grid 23 through the grid terminal 28.As long as an open circuit exists between terminals 28 and 26, condenser8| is charged by grid current flowing during the half cycles whenterminal 25 is positive and the charge provides a suflicient negativegrid bias to maintain tube 20 non-conductive during the half cycles whenterminal 26 is positive. Relay 29 is, therefore, deenergized. Whenterminal 28 is connected to terminal 26, or the resistance between theterminal is substantially reduced, as by the dropping of a contactmember i3 due to thread breakage, the current through resistance 82 issubstantially increased, and the potential drop across the resistance,during the half cycles when terminal 26 is positive, overcomes the biasapplied by condenser 81 and renders the tube conductive. Relay 29 isthen energized and closes contact 35. It is thus apparent that, uponbreakage of a thread M, the associated drop contactor l3 closes acircuit between the input terminals 26 and 28 and effects operation ofthe electronic relay l8, and therefore of the relay 29 and the switch35. This switch may control alarm or motor circuits involving relativelygreat current and power, examples of which are hereinafter set forth indetail.

Referring now to Fig. 2, there is illustrated in part a loom havinvertical supporting columns and 4| and a plurality of contactor devicesI5, each including the elongated conductive bars l0 and H. Groups ofthreads I 4, which may be warp-forming threads, are arranged in banks,of which only one is here illustrated, and supported between thevertical columns 40 and 4| by horizontal runners 42. A pair of conductorbars 10 and H is arranged beneath each bank of threads l4 and upon eachthread is suspended a drop contactor 13, as illustrated in greaterdetail in Fig. 1. Each first bar [0 is grounded and the second bars Hare all connected in parallel to the grid input terminal 28 of anelectronic relay [6, again as shown in Fig. l. The second bars H may beconnected together in parallel as shown, or in series if desired, therebeing no difference in the result of either of these connections, sincethe drop contactors l3 all cause switching action in parallel, and ifany one of them drops, a switching action will take place and cause theelectronic relay IE to become operative. To the output terminals 44 and45 of the switch 35 there is connected an alarm 46, which may have anydesired characteristics, so that upon the dropping of any drop contactorI3 a circuit is closed causing operation of the alarm 46 through therelay l6 and switch 35. A particular type of alarm that is suitable foruse with a loom is discussed hereinafter in connection with Fig. 4. s

Fig. 3 illustrates another arrangement of electronic relays\l6 andalarms 46 which may be adopted to provide a signal that will enable onenot only to stop the loom, but also to identify the bank in which thebroken thread exists. The left hand half of the loom of Fig. 2 is shownin part, including one vertical supporting column 40 and the appropriateends of the three sets of contactor bars in and II. As heretofore, thefirst conductive bar in is grounded. However, each second conductive barH is connected to the input grid terminal 28 of an individual associatedelectronic relay 16, the relays being distinguished by Roman numerals I,II and III. The negative terminal 25 of each electronic relay isgrounded, so that the signal input circuit for each electronic relay isthe same as in Fig. l. A separate alarm 46 I, II or III is operated byeach relay. Thus, when a thread breaks in any bank, the alarm 46 of thatbank will operate, and in addition to giving an alarm, will indicate inwhich bank the breakage occurred.

To illustrate how the invention may be adapted to indicate the bank inwhich a thread breakage occurs and simultaneously automatically stop theloom, reference is made to Fig. 4. There in dotted line boxes isenclosed the apparatus of three identical suitable alarms 46 which areadapted to accomplish these purposes. The alarms 46 are distinguished byRoman numerals I, II and III in accordance with the plan of Fig. 3. Ineach alarm 46 there is included a normally closed switching relay 50 anda lamp 5i. The normally closed relays 50 are all arranged so that theirswitches 52 are in series with the power to a motor M, which may providethe driving power for the loom. Power is brought to the motor M throughappropriate input terminals 54 and 55 and wires 58 and 59, and to theseterminals there are also connected in parallel two wires 56 and 51 tocarry power for energizing the relays 59 in the alarms 46 In seriesconnection with each relay 50 is the switch 35 of the associatedelectronic relay I6, I, II or III (illustrated in Fig. 3), and a lamp5i. The alarms 46 are all connected in parallel to the power inputterminals 55 and 55.

When a switch 35 closes, the relay 50 of the associated alarm 46 willoperate and open itsswitch 52, thus interruptin power to the motor M andshutting down the loom. Simultaneously, the power for the relay 50 willflow through the associated lamp 5|, and the lamp will light andindicate that the thread bank with which the particular alarm 46 andswitch 35 are asso ciated has in it a broken thread. A current returnpath is provided for each alarm 46 to the terminal 54 through a directwire 56. An alternative return path may be had to terminal 54 throughthe unlighted lamps 5i and non-energized relays 50 of the remainingalarms 46 However, this alternative return path offers a relativelylarge impedance to the flow of electrioal current, and therefore themajor portion of return current will fiow through the direct wire 56,and the remaining lamps 5i will not be lighted nor will the other relays50 be operated. Thus the apparatus of Fig. 3 may be adaptedsimultaneously to shut off the loom and indicate the bank in which athread-breakage exists, whenever the breakage of a thread l4 occurs.

As hereinabove stated, relay apparatus "3 of the electronic type isadapted to become operative not only when a positive connection is madebetween the grid terminal 26 and terminal 26, but also when theresistance between terminals tive switching apparatus as illustrated inFig. 6.

The apparatus of Fig. comprises an elongated fixed condenser plate 60,and a plurality of movable smaller condenserplates 6|. As illustrated incross section-holes 63 are provided in each movable plate SI for guidingthe plate upon vertical poles 62 mounted on the fixed plate 60. The

poles 62 may be 01' any suitable insulating materiaT such as hard rubberor polystyrene. The

- movable plates 8| are adapted to fall toward the fixed plate Blifandto come to rest on the enlarged base portions 84 of the poles 62. A hook85 is provided on each movable plate 6| for attachment to a thread M insubstantially the same manner as the drop contactors iii are so attachedin Fig. 1. Flexible partly coiled wires 68 furnish conductive contactbetween the movable plates 6| and a bus bar 61 which is furtherconnected to a terminal 68. This last-mentioned terminal 68 is adaptedto be connected to the input grid terminal 28 of the electronic relayapparatus IE or similar apparatus. The fixed condenser plate 80 isgrounded, or may be connected to the second input terminal 26.

When the hooks 65 are attached each to a thread (not shown), the movableplates 6| are each'held a predetermined distance away from the fixedplate 60. However, when a thread breaks, the associated movablecondenser plate GI falls until it comes to rest on the base portions 6|of the guiding poles 62, thus decreasing the distance between the twocondenser plates 60 and 6|. This decrease in distance will effect areduction in the capacitive reactance of the apparatus, and likewise inthe impedance of the input circuit of an electronic relay l6 to which itmay be connected, thus having an efiect of the same nature as thedropping of a conductive contactor ii to Fig. 1 and causing operation ofthe electronic relay apparatus in the same manner as discussed above. Itis to be noted that there is no conductive contactbetween the plates 60and BI and hence no possibility of sparking between those plates, andthus the hazard of fires and explosion caused by sparking in thepresence of lint, is completely eliminated inthis apparatus.

The switching mechanism of Fig. 6 which is illustrated mainly inelectrical scheme, comprises a transformer 10 having a primary winding Hand a short-circuited secondary winding 12. The primary H has one endgrounded and the other end connected to a terminal 18 which, like theterminal 6! of the apparatus of Fig. 5 is adapted to be connected to thegrid input terminal 28 of the electronic relay apparatus IS. Athread-engaging hook 13 is provided on the short-circuited secondary 12and has the same purpose as the hook .65 of the capacitor switchingapparatus in Fig. 5. The short-circuited secondary 12 is adapted torotate about a point 14 as an axis and is normally maintained in thevertical position illustrated in Fig. 6 when the hook I! is resting on athread (not shown). The weight of the secondary is preferably sodistributed about the point ll-that it will tend to fall to adisposition in which it is substantially parallel to the primary Ii whennot otherwise constrained.

When alternating current fiows in the primary has a relatively .lowimpedance, and a relatively 1 6 winding II and whenthe secondary windingIt is disposed substantially p p ndicularly thereto, a relatively highimpedance is offered to thefiow or current in the primary winding.However,

when the short-circuited secondary I2 is substantially parallel to theprimary 1 I, the primary than large current may be permitted topass.Thus, upon the breakage of a supporting thread (not shown) with whichthe hook I! may have been engaged, the short-.circuited secondary 12will fall and permit the passage of a larger current through the primaryH by lowering its inductive reactance. Like the capacitive switch 01'Fig. 5, the apparatus of Fig. 6 is adapted to lower the impedance of theinput circuit of electronic relay apparatus l6 whenv properly connectedthereto. This apparatus also will permit I spark-tree thread-breakdetection.

Obviously various changes may be made in the above-described articlesand different embodiments of the invention can be made without departing.from the scope thereof. It is therefore intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative only, and not in a limiting sense,and that the invention is to be limited only by the prior art and thespirit or the appended claims.

What is claimed is:

1. For machines for the weaving, spinning and the like of filamentarymaterial, filament-break detecting means comprising: an electrondischarge device having an anode, cathode, and con- 'trol electrode; anoutput circuit including said anode and cathode; and an input circuitincluding said cathode and control electrode; a plurality of electricalreactance controlling means arranged in mutually parallel connection insaid input circuit and each supported by an individual filament in apredetermined disposition but adapted upon breakage of the supportingfilament to assume? and maintain a new disposition and thereby alter theelectrical character 01' said input circuit; and operator means adaptedto be energized by said output circuit.

2. In combination with a machine for operatingupon a filament, means fordetecting the breakage of said filament comprising: an electrondischarge device having an anode, cathode and control electrode; anoutput circuit including said anode and cathode; a variable capacitancecomprising, a movable member supported by said filament, and a fixedmember; an input, circuit including said cathode, control electrode, and

capacitance, and adapted to render and maintain said discharge deviceconductive upon the breakage of said filament; and operator meansadapted to be energized by said output circuit.

3. In combination with a machine for operating upon a filament, meansfor detecting the breakage of said filament comprising: an electrondischarge device having an anode, cathode and control electrode: anoutput circuit including said anode and cathode; a variable inductancehaving a movable member the position of which is altered upon breakageof said filament; an input circuit including said cathode, controlelectrode and inductance, and adapted to render and maintain saiddischarge device conductive upon the breakage of said filament andoperator means adapted to be energized by said output circuit.

4. A thread break detection device comprising: an electron dischargedevice having an anode,

contact with said bar; an input circuit including 30 said cathode, adevice for storing electrical energy, and said detecting impedance, andadapted to render and maintain said discharge device conductive uponthread breakage; and operator means adapted to be energized by saidoutput circuit. s

5. A thread break detection device comprising: an electron dischargedevice having an anode, cathode, and control electrode; an outputcircuit including said anode, said cathode; a variable capacitancecomprising a movable member adapted to be supported by a thread, and afixed member; an input circuit including said cathode, controlelectrode, and capacitance, and adapted to render and maintain saiddischarge device conductive upon thread breakage; and operator meansadapted to be energized by said output circuit.

6. A device according to claim in which said capacitance comprises apair of parallel plates maintained in alignment byinsulating studs.

'7. A thread break detection device comprising: an electron dischargedevice having an anode, cathode, and control electrode; an outputcircuit including said anode, said cathode; a variable inductance havinga movable member, the position of which is altered on thread breakage;an input circuit including said cathode, control electrode andinductance, and adapted to render and maintain said discharge deviceconductive upon thread breakage; and operator means adapted to beenergized by said output circuit.

8. A device according to claim '1 in which said inductance comprises afixedinductance coil, and a movable coil rotatable with respect to saidfixed coil.

9. For machines for the weaving, spinning and the like of filamentarymaterial, filament-break detecting means comprising; an electrondischarge device having an anode, cathode and control electrode; anoutput circuit including said anode and cathode; an input circuitincluding said cathode, said control electrode, and a capacitance; aplurality of electrical impedance controlling means arranged in mutuallyparallel connection in said input circuit and each supported by anindividual filament in a predetermined position but adapted uponbreakage of the supportingiilament to assume and maintain a newdisposition and thereby alter the electrical character of said inputcircuit; operator means adapted to be energized by said output circuitupon breakage of any one of said filaments; and means controlled by saidoperator means ior interrupting a power circuit independent of saidoutput circuit and for providing a thereafter continuing indicationthatsaid breakage has occurred.

10. In combination with a machine for operation upon \filaments, meansor detecting the breakage of any of said filaments comprising: I

an electron discharge device having an anode, a cathode and controlelectrode; an output circuit including d anode and cathode; an inputcircuit lnciu ing said cathode, said control electrode, and acapacitance; a plurality of impedance controlling means arranged inmutually parallel connection in said input circuit, each 0! saidcontrolling means being supported by one of said filaments in apredetermined disposition,

but adapted upon breakage of its supporting filament to assume andmaintain a new disposition and thereby alter the electrical character ofsaid input circuit; and operator means adapted to be energized by saidoutput circuit, said operator means consisting in means for. indicatingthe breakage of said filament and means for interrupting a power circuitindependent of said output circuit, and being adapted upon the breakage01 said filament to interrupt said power circuit and simultaneously toprovide a thereafter continuing indication that said breakage hasoccurred.

11. In combination with a machine for operating upon filaments, meansfor detecting the breakage oi any of said filaments comprising: anelectron discharge device having an anode, cathode and controlelectrode; an output circuit including said anode and cathode; an inputcircuit including said cathode, said control electrode, a capacitanceand a plurality of parallel connected detecting impedances, and adaptedto render and maintain said discharge device conductive upon thebreakage of any of said filaments; and operator means adapted to beenergized by said output circuit and when eners zed to interrupt thepower supply to said ma chine and to actuate indicating means.

ARTHUR G. B. METCALF.

REFERENCES CITED The following references are of record in the the ofthis patent:

UNITED STATES PATENTS Number OTHER REFERENCES Textile World, July 1945,pa es 83-90, "Elec- 5 tronics at Work for Textiles, by H. E. Reed.

(Copy in Scientific Library.)

